of "starting point" begins right now. >>> he can hardly speak but terrorsuspectdzhokhartsarnaevistalking or at least communicating, big new developments this morning in the boston marathon bombing investigation. cnn's jake tapper has learned that tsarnaev is communicating with investigators, and claims that he and his brother pulled off last week's bombing of the marathon and also that their motivation seems to be that of jihadists. cnn's chief washington correspondent and anchor of "the lead" jake tapper is with us this morning. and jake, what are your sources telling you about these communications. >> u.s. government source tells me that in these preliminary interviews with dzhokhar tsarnaev, and he underlines they're preliminary, all the information that dzhokhar is giving needs to be checked out, that investigators are not taking his word for it, but what he is saying is that first of all, there were no foreign groups involved in the attacks. second, he's saying that there is an online component to how these brothers were radicalized. they watched videos online. they got information

seedzhokhartsarnaevjustafter the murder of an m.i.t. police officer. >> first the headline from the suspect dzhokhar tsarnaev, we acted alone. a u.s. government source quotes the surviving suspect saying the older brother was the master mind and they had no international ties to terror groups. he also says the men were motivated by radical islam and the jihadist goal of waging a holy war. they learned to make their bombs from readily available instructions on the internet. deborah has the latest from new york. >> wolf, we can tell you investigators are painting a much fuller picture of the parents and the life this tamerlan tsarnaev was living. his pull here in the united states and his life over in the russian caucasus. what we can tell you this morning is that the m.i.t. officer that was shot to death did not radio into dispatch to request a description of the suspect and he did not alert dispatch he was responding to the two men who apparently came up to him totally unaware. he was shot four to five times according to a source. it took at least nearly 13 minutes to actually f